The next generation of artificial intelligence programs will require the ability to organize knowledge as groups of active objects. Each object should have only its own local expertise, the ability to operate in parallel with other objects, and the ability to communicate with other objects. Artificial Intelligence programs will also require a great deal of flexibility, including the ability to support multiple representations of objects, and to incrementally and transparently replace objects with new, upward-compatible versions. To realize this, we propose a model of computation based on the notion of an actor, an active object that communicates by message passing. Actors blur the conventional distinction between data and procedures. The actor philosophy is illustrated by a description of our prototype actor interpreter Act 1.
